Can't snap to some polylines? Ribbon misbehaving? Here's why.

Scale Lists Revisited
In November 2007, January 2008, and March 2008, I described the many problems presented by AutoCAD 2008's scale lists. The good news is that AutoCAD 2009 has addressed some of these problems:

Inserting a drawing no longer brings in all the scales associated with that drawing, only those ones that are in use.

If you open a drawing with more than 100 scales, AutoCAD 2009 prompts you to ask if you want to reset the drawing to the default scale list.

If you open a drawing that has an attached xref containing more than 100 scales, a Command line message advises you of that fact.

The scale list control contains a toggle that allows you to hide those scales that are inherited from xrefs. This toggle is on by default, meaning that you will not usually see the dreaded _XREF_XREF scales.

The MEASUREMENT system variable, which is used to identify whether a drawing is metric, is no longer completely ignored. It is checked during a scale list reset, reducing the likelihood that metric users will see inch-based scales.

The Scalelistedit dialog box now allows you to use the Delete button on multiple scales, even if one or more of the selected scales can't be deleted. This makes it much easier to manually delete unused scales.

These fixes largely are measures to hide problems rather than completely remove them, and therefore fall a bit short of the complete overhaul I was hoping for. However, Autodesk deserves credit for significantly reducing the harm caused by the AutoCAD 2008 scale list implementation.

Some Polylines Are Snappier than Others (2009)Submitted by Chris Cowgill
As you recover from the shock of the new and start using AutoCAD 2009 for real work, you may notice that your object snaps don't work on some polylines. This may seem random, but it's not. For the problem to occur on a given polyline, three conditions must be met:

It must be an old-fashioned "heavy" polyline, not a lightweight one. In Properties and Quick Properties, such a polyline is described as a 2D polyline rather than just a polyline. The List command describes it as a polyline object rather than an lwpolyline. This should not be confused with what Properties calls a 3D polyline, but List calls a polyline.

It must have continuous linetype generation turned on. That's the property of a polyline that tells AutoCAD to draw its linetypes based on the polyline as a whole, rather than on each individual segment.

It must have a continuous linetype, whether that is based on the object's layer or not.

That may seem like an unlikely combination, but it is more common than you might think. There are still third-party products and LISP routines that create or expect heavy polylines, so some users set the PLINETYPE system variable to 0 as soon as they receive a new AutoCAD. Similarly, many users set the PLINEGEN system variable to 1 in their templates or startup routines, because most people want their linetypes to go around corners in polylines. Such people are likely to have large numbers of drawings containing large numbers of polylines that meet all three conditions.

Workaround: There's no way to persuade AutoCAD 2009 to snap to such objects, so you will need to change them such that not all of the three conditions are met. It's unlikely you will want to change the linetype of the objects, so that just leaves the first two conditions to play with. You can convert the polylines from light to heavy using the undocumented Express Tools command Convertpoly. Alternatively, you can turn off continuous linetype generation in selected polylines using either the Properties palette or the Ltype gen option in the Express Tools command Mpedit.

Semitransparent Ribbon (2009)
One of the things that Autodesk's Ribbon does better than Microsoft's is offer you several options about minimizing the ribbon, or even doing away with it altogether. The main way in which you can choose between your ribbon minimize options is by picking a little oval button on the ribbon tab title bar. It's a three-way toggle. Pick it once and the ribbon shrinks to show only the tab and panel titles. Pick it again and the panel titles vanish too. Pick it a third time and you're back to a full ribbon again.

What's wrong with this? Nothing, as long as you do it only between commands. If you do it transparently (i.e., while a command is active), it leaves the ribbon in a strange state.

Minimizing the ribbon during the Line command.

If the ribbon is in its tab-and-panel-title state, don't be tempted to pick the little button to get at something in the ribbon. It won't work properly, and you will end up with just a little sliver of ribbon visible. Instead, hover over a panel title to make the contents visible.

Workaround: None really, other than "don't do that." If you do happen to do it, just wait until the command is over, then pick the button again until the ribbon is fixed.

About the Author: Steve Johnson

In her easy-to-follow, friendly style, long-time Cadalyst contributing editor and Autodesk Technical Evangelist Lynn Allen guides you through a new feature or time-saving trick in every episode of her popular AutoCAD video tips. Subscribe to the free Cadalyst Video Picks newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!